[FFmpeg-user] problem capture desktop

[Juan carlos Rebate]

Hello, I am trying to capture video and audio from a game in windows,
but since my pc does not have devices to do it (theoretically yes but
ffmpeg does not detect it), I installed some virtual devices but when
I call the command it gives me an error
fmpeg -f dshow -i video="screen-capture-recorder" -vcodec libx264 -r
25 -crf 10 -i audio="virtual-audio-capturer" -acodec mp3 output.mp4
ffmpeg version 4.2.3 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.3.1 (GCC) 20200523
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libdav1d --enable-libbluray --enable-libfreetype
--enable-libmp3lame --enable-libopencore-amrnb
--enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus
--enable-libshine --enable-libsnappy --enable-libsoxr
--enable-libtheora --enable-libtwolame --enable-libvpx
--enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265
--enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib
--enable-gmp --enable-libvidstab --enable-libvorbis
--enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex
--enable-libxvid --enable-libaom --enable-libmfx --enable-amf
--enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc
--enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
leaving aero onInput #0, dshow, from 'video=screen-capture-recorder':
  Duration: N/A, start: 8918.676000, bitrate: N/A
    Stream #0:0: Video: rawvideo, bgr0, 800x600, 30 fps, 30 tbr,
10000k tbn, 10000k tbc
Unknown decoder 'libx264'
the strange thing is that if I delete the part that refers to the
audio if the video codec recognizes me, what am I doing wrong?